EVALUATION ON THE THERMAL AND STRUCTURAL PROPERTIES OF COPPER ALUMINUM OXIDE (Cu-Al2O3) THIN FILM ON AL SUBSTRATE: EFFECT OF ANNEALING TEMPERATURE

Layer stacking technique is incorporated in the deposition of copper aluminium oxide (Cu-Al2O3) thin films on Al substrate using RF magnetron sputtering. The Cu/Al2O3 stack is sputtered using Cu and Al2O3 target at ambient temperature and then annealed to yield the resultant Cu-Al2O3 films. The structural properties of the films are investigated through X-ray Diffraction (XRD) whereas the chemical structure of the films is studied using Fourier-transform infrared (FTIR). The thermal conductivity analyzer is used to evaluate the thermal properties of coated film on the Al substrate. XRD analysis revealed that the synthesized films are polycrystalline film composed mainly of CuAl2O4 phase along with Al2O3 and CuO phases. The thermal properties of Cu-Al2O3 coated Al substrates showed improvement in terms of thermal conductivity and diffusivity compared to bare Al substrate. The Cu-Al2O3 sample annealed at 400∘C exhibited a significant difference in thermal conductivity (Δk=11W/mK) compared to bare Al. The difference in thermal conductivity displayed by the annealed sample verified that TIMs did enhance the thermal path of entire substrate by allowing the heat to dissipate to surrounding environment more efficiently, thereby improving the heat dissipation system. From the results observed, it can be concluded that Cu-Al2O3 coated Al substrate can be made as alternative TIM in thermal management application.